The Active Directory Federation Services (AD FS) role service is installed on this server. When the OS upgrade is complete, ...

The Active Directory Federation Services (AD FS) role service is installed on this server.  When the OS upgrade is complete, you will need to reinstall the role service and then reconfigure the federation service by adding the node to an existing Windows Server 2012 R2 or later AD FS farm. For more information see http://go.microsoft.com/fwlink/?LinkID=518375.